Ejector pumping systems

ABSTRACT

An ejector pumping system according to this disclosure includes an impeller pump driven by a turbine for pumping monopropellant to a catalyst pack where the monopropellant is decomposed to form exhaust gas. The turbine is driven by exhaust gas from the catalyst pack.

United States Patent Inventors George \'.Brereton [50] Field of 60/259, Sacramento; 39.46; 417/405; 290/1 16 0 m C a C n e r m e R Q U an fin 8g hO s 8 mm 0 mn mm am mm a K n 1m MB n RJ UNITED STATES PATENTS 1/1953 Houdry........................

Carmichael, all of, Calif. Appl. No 842,912

2,624,172 60/39.46 2,949,007 8/1960 Aldrich et 60/259 Primary Examiner-Robert M. Walker [22] Filed July 18,1969

Patented July 13, 1971 Assignee 73 A t-Ge al C t' I 1 El M fnle, orpom on Attorneys-Edward O. Ansell and D. Gordon Angus [54] EJECTOR PUMPING SYSTEMS 10 Claims, 2 Drawing Figs.

pumping system according to this pellet pump driven by a turbine for t pack where the posed to form exhaust gas. The turu a P e N m m C e c a m o m H. t r. nm O a t m w m n amm m 650 X TS ie mmmw :moh Timde e Am mm RS.mD. TbPo mm mm .1 l AdPmb 5 2 @OMO 2 J 9 7 2 d 42 0 F L C C S t U .d l 5 5 52 1 TO AFTERBURNER HECTOR PUMPING SYSTEMS This invention relates to ejector pumping systems, and particularly to self-contained, self-energized ejector pumping systems for pumping a secondary fluid.

l-leretofore, pressure-fed jet pumps have been used 'as jet ejectors for pumping secondary fluids, such as air for wind tunnels. Pressure-fed jet pumping systems have required a pressurized source of hydrogen peroxide or other monopropellant source of primary fluid, which can be both dangerous and costly. Furthermore, in prior jet ejectors having catalyst packs, the propellant flow to the catalyst pack has been at full system pressure, even when the system is started, because the propellant is fed from prepressurized sources. The full pressure monopropellant, when applied to the catalyst pack during start up of the system, has flooded the catalyst pack and has reduced the catalyst life.

it is an object of the present invention to provide a jet ejector system which is self-energizing thereby eliminating the requirement for a high-pressure supply of propellant.

Another object of the present invention is to provide an ejector pumping system wherein the propellant is applied to the catalyst pack at relatively low pressure during startup and the pressure of propellant to the catalyst pack increases according to the decomposition characteristics of the catalyst pack until the system reaches full system flow.

Another object of the present invention is to provide a monopropellant ejector pumping system which is self-contained and self-energized.

Another object of the present invention is to provide a selfcontained, self-energized monopropellant ejector pumping system requiring no subsystem cooling.

in accordance with the present invention monopropellant is pumped by means of an impeller which is driven by a turbine, which is driven by the exhaust gases from a catalyst pack. The monopropellant pumped by the impeller is delivered to the input of the catalyst pack where it decomposes. The exhaust gases are used to drive the turbine, and are ejected through suitable jet nozzles.

In accordance with an optional and desirable feature of the present invention, multiple catalyst packs are used having their inlets connected to the outlet of the impeller. The exhaust from one or more of the catalyst packs may be utilized to drive the turbine thereby increasing the pressure of the monopropellant delivered to the catalyst packs.

The above and other features of this invention will be more fully understood from the following detailed description and the accompanying drawings, in which:

FIG. 1 is a schematic flow diagram of an ejector pumping system in accordance with the present invention; and

FIG. 2 is a schematic flow diagram of an ejector pumping system in accordance with a modification of the system illustrated in FIG. 1 and illustrates the presently preferred embodiment of the present invention.

Referring to the drawings where the same reference numerals are used throughout the drawings to indicate similar apparatus, and particularly to H6. 1, there is illustrated an ejector pumping system in accordance with one embodiment of the present invention. The ejector system as illustrated in FIG. 1 includes a supply 10 of monopropellant such as hydrogen peroxide (H or hydrazine (N H Monopropellant is admitted to supply tank through inlet conduit lll. Also, inlet conduit 12 is provided to tank 10 for admitting a pressurizing fluid, preferably an inert gas such as nitrogen, to pressurize the monopropellant in tank 10. As will be more fully understood hereinafter, the pressure of the monopropellant may be maintained at about 3 to 100 p.s.i.g. The pressure of the pressurizing fluid is regulated by regulating valve 13 which provides a constant pressure output and by shutoff valve 14. Also, the pressurizing fluid is connected to conduit 15 through valve 16 for purposes to be hereinafter explained.

A relief tree 17 comprising relief valve 18 and valve 19 is connected to supply tank 10 and vented to the atmosphere at 20.

Supply tank 10 has a first outlet through conduit 21 to shutoff valve 22 having an output connected to conduit 15. A boost pump (not shown) may be provided in conduit 21 if monopropellant supply pressure is too low to maintain independent flow of propellant through the system. Supply tank 10 also has a second outlet through conduit 23 to shutoff valve 24 whose outlet is connected to conduit 25. Conduit 25 is connected to the inlet of start pump 26 whose outlet is connected to the inlet of three-way control valve 27. Shutoff valves 22 and 24, pump 26, and'thr'ee way valve 27 are controlled by controller 29 in a manner to be hereinafter explained.

Conduit 15 is connected to the inlet of impeller 30 of turbopump 31. Impeller 30, which may, for example, comprise a plurality of impeller blades (not shown) is driven by shaft 32 which in turn is driven by turbine 33 of turbopump 31. Conduit 34 is connected to the output of impeller 30. impeller 30 generates a differential pressure of monopropellant between its input and output to increase the flow of propellant thereby increasing the pressure of monopropellant within conduit 34 over that in conduit 15. Conduit 34 is also connected to the inlet of impeller 35 of turbopump 36. The output of impeller 35 isconnected to conduit 37. impeller 35 is driven by means of shaft 38 which in turn is driven by turbine 39 of turbopump 36. A portion of the output of impeller 35 is diverted through conduit 40 through the orifice 41 and to conduit 42 which is connected to the inlet of turbine 33. The outlet of turbine 33 is connected to conduit 34.

As illustrated in the drawings, conduit 34 is also connected through valve 43 to the atmosphere so that the monopropellant in conduit 34 may be dumped to the atmosphere. Also, impeller 30 is vented to the atmosphere through shutoff valve 44 and conduit 40 is vented to the atmosphere through shutoff valve 45. Conduit 37 is connected through valve 53 to the atmosphere so that monopropellant within conduit 37 may be dumped to the atmosphere.

Output conduit 37 and impeller 35 is connected through check valve 46 and throttle valve 47 to conduit 48 which in turn is connected to the inlet of catalyst pack 49.

The outlet of catalyst pack 49 is connected through conduit 54 to the inlet of turbine 39. The outlet of turbine 39 is connected through conduit 55 to nozzles 56.

In the event that the pumping system according to the present invention is used for rocket motors, jet engines, or the like, three-way valve 27 has one of its outlets connected through check valve 50 to conduit 48. The other outlet of three-way valve 27 is connected through check valve 51 to conduit 52, which may, for example, be connected to the afterbumer of the rocket or jet engine. Of course, if the pumping system is used in a supersonic wind tunnel, there is no afterbumer and valve 27, valve 51 and conduit 52 may be eliminated, and a connection be provided between pump 26 and valve 50.

In operation of the ejector system illustrated in FIG. 1, control 29 is operated to open shutoff valves 22 and 24 and to operate on three-way valve 27 so as to divert fluid through check valve 50 and to operate pump 26 to pump monopropellant through check valve 50 through conduit 48. At the same time, nitrogen gas pressurizing the monopropellant forces monopropellant through impeller 30 of turbopump 31, through impeller 35 of turbopump 36, through valves 46 and 47 to conduit 48. The monopropellant is decomposed by means of catalyst contained in catalyst pack 49 and the exhaust gases are discharged through conduit 54 to drive turbine 39. The exhaust gases then pass through conduit 55 and are discharged through jets 56. By way of example, the jets may comprise a plurality of converging-diverging nozzles through which the hot exhaust gases exit at a supersonic velocity.

As turbine 39 begins to drive impeller 35, the pressure of the monopropellant appearing in conduit 37 increases, thereby increasing the inlet pressure of propellant to the catalyst pack. Also, as impeller 35 increases the pressure of monopropellant in conduit 37, likewise, the pressure monopropellant in conduit 40 is increased thereby driving turbine 33 of turbopump 31. As turbine 33 operates on impeller 30, the impeller 30 increases the pressure of monopropellant in conduit 34 thereby increasing the pressure of the monopropellant to the input of impeller 35. Furthermore, the pressurized monopropellant driving turbine 33 is exhausted back througli impeller 35 and is pressurized therein. The entire cycle continues until the pressure in conduit 48 rises to the design pressure, for example about 5000 p.s.i.g. By way of example, turbopump 31 may increase the pressure of monopropellant from about 20 p.s.i.g. in conduit 15 to about 500 p.s.i.g. in conduit 34 and turbopump 36 may increase the pressure of the monopropellant from about 500 p.s.i.g. to about 5,000 p.s.i.g. Thus, the pressure of monopropellant introduced to catalyst pack 49 at full throttle may be approximately 5,000 p.s.i.g.

When full running velocity is achieved, controller 29 may be operated to close valve 24 and turn off electric pump 26. Alternatively, and as an optional mode of control, valve 27 may be operated to its second position to direct monopropellant to the after burner through conduit 52.

The exhaust gases discharged through nozzles 56 form the primary fluid of a pumping system for pumping secondary fluid, such as air. The air in area 62 is at a total pressure P in the region upstream of the nozzles 56. As primary exhaust fluid is discharged through nozzles 56, the total pressure downstream from the nozzles 56 in the area 60 is P and is higher than P,. Secondary fluid flows in the direction of arrows 61 by virtue of the jet pumping action of the high velocity gases exhausted from the nozzles 56. It is preferred that if the secondary fluid is oxidizer rich, such as air, the monopropellant in supply be an oxygen-rich monopropellant such as hydrogen peroxide. On the other hand, if a secondary fluid is fuel rich, a fuel-type monopropellant, such as hydrazine, would be preferred to prevent combustion of the mixture in the diffuser section of the jet pump.

FIG. 2 illustrates the presently preferred embodiment of the ejector pumping system according to the present invention wherein the outlet conduit 37 of impeller 35 is connected through check valve 57 and multiple catalyst packs 58 to jets 59. In this form of the invention, conduit 37 operates to divide high velocity monopropellant into two paths. A portion of the monopropellant is diverted through conduit 48 to be decomposed in catalyst pack 49 to drive turbine 39 before being exhausted through nozzles 56 while the remainder of the monopropellant is decomposed in catalyst pack 58 and exhausted through nozzles 59.

The system illustrated in FIG. 2 offers the advantages that a separate catalyst pack may be associated with each nozzle array, the propellant mass is distributed when the propellant is in its liquid, rather than gaseous, state, and, in certain rocket or jet engine applications, the system may require less weight than the system illustrated in FIG. 1 for the same flow rates.

As in the case of FIG. 1, the ejector pumping system illustrated in FIG. 2 is throttled by means of throttle valve 47. Also, the system may be evacuated by opening all the valves to permit release of system fluids. Valve 16, when opened, permits removal of monopropellant from the input ofimpeller 30 by flushing with inert gas.

The present invention thus provides an ejector pumping system which does not require a high-pressure source of monopropellant. The system is self-energizing and is self-contained. The system is easily shut down by merely closing shutoff valves 22 and 24 by suitable operation of controller 29 and by suitably controlling valve 47 so as to prevent pump cavitation.

This invention is not to be limited by the embodiments shown in the drawings and described in the description, which are given by way of example and not of limitation.

What we claim is:

1. Apparatus comprising: supply means for supplying propellant; impeller means having an input adapted to receive propellant from said supply means and having an output; catalyst means for receiving the propellant from said output and for decomposing said propellant to form exhaust gases;

turbine means adapted to be driven by said exhaust gases from said catalyst, said turbine means being adapted to drive said impeller means so that said impeller means pumps propellant to its output at a pressure higher than at its input; and outlet means for exhausting said exhaust gases at a high velocity.

2. Apparatus according to claim I further including second impeller means having an input connected to said supply means and having an output connected to the input of said first-named impeller means, and second turbine means adapted to receive pressurized propellant from the output of said first-named impeller means to drive said second impeller means so that said second impeller means pumps propellant to its output at a higher pressure than the pressure of the supply.

3. Apparatus comprising: supply means for supplying propellant; first impeller means having an input adapted to receive propellant from said supply means and having an output; a second impeller means having an input adapted to receive propellant from said output of said first impeller means and also having an output; catalyst means for receiving propellant from said output of said second impeller means and for decomposing said propellant to form exhaust gases; a first turbine means adapted to be driven by said exhaust gases from said catalyst, said first turbine means being adapted to drive said second impeller means so that second impeller means pumps propellant to its output at a pressure higher than at its input; a second turbine means adapted to receive pressurized propellant from the output of said second impeller means and adapted to drive said first impeller means so that said first impeller means pumps propellant to its output at a higher pressure than the pressure of the supply; and outlet means for exhausting said exhaust gases.

4. Apparatus according to claim 3 wherein the propellant which drives said second turbine means is returned to the input to said second impeller means.

5. Apparatus according to claim 3 further including at least a second catalyst means for receiving propellant from said output of said second impeller means and for decomposing propellant to exhaust gases, and at least a second outlet means for exhausting the exhaust gases from said second catalyst means.

6. An ejector pumping system for pumping secondary fluid comprising: nozzle means so disposed and arranged with relation to the secondary fluid that discharge of primary fluid through the nozzle means causes the pumping of secondary fluid; supply means for supplying propellant; impeller means having an input adapted to receive propellant from said supply means and having an output; catalyst means for receiving propellant from said output and for decomposing said propellant to form said primary fluid; turbine means adapted to be driven by primary fluid from said catalyst, said turbine means being adapted to drive said impeller means so that said impeller means pumps propellant to its output at a pressure higher than at its input; and outlet means for exhausting said primary fluid to said nozzle means.

7. Apparatus according to claim 6 further including second impeller means having an input connected to said supply means and having an output connected to the input of said first-named impeller means, and second turbine means adapted to receive pressurized propellant from the output of said first-named impeller means to drive said second impeller means so that said second impeller means pumps propellant to its output at a higher pressure than the pressure of the supply.

8. Apparatus according to claim 7 wherein the propellant which drives said second turbine means is returned to the input to said first-named impeller means.

9. Apparatus according to claim 6 further including second catalyst means for receiving propellant from said output and for decomposing propellant to primary fluid, and second nozzle means for exhausting the primary fluid from said second catalyst means to pump said secondary fluid.

10. Apparatus according to claim 5 wherein the propellant is a monopropellant. 

1. Apparatus comprising: supply means for supplying propellant; impeller means having an input adapted to receive propellant from said supply means and having an output; catalyst means for receiving the propellant from said output and for decomposing said propellant to form exhaust gases; turbine means adapted to be driven by said exhaust gases from said catalyst, said turbine means being adapted to drive said impeller means so that said impeller means pumps propellant to its output at a pressure higher than at its input; and outlet means for exhausting said exhaust gases at a high velocity.
 2. Apparatus according to claim 1 further including second impeller means having an input connected to said supply means and having an output connected to the input of said first-named impeller means, and second turbine means adapted to receive pressurized propellant from the output of said first-named impeller means to drive said second impeller means so that said second impeller means pumps propellant to its output at a higher pressure than the pressure of the supply.
 3. Apparatus comprising: supply means for supplying propellant; first impeller means having an input adapted to receive propellant from said supply means and having an output; a second impeller means having an input adapted to receive propellant from said output of said first impeller means and also having an output; catalyst means for receiving propellant from said output of said second impeller means and for decomposing said propellant to form exhaust gases; a first turbine means adapted to be driven by said exhaust gases from said catalyst, said first turbine means being adapted to drive said second impeller means so that second impeller means pumps propellant to its output at a pressure higher than at its input; a second turbine means adapted to receive pressurized propellant from the output of said second impeller means and adapted to drive said first impeller means so that said first impeller means pumps propellant to its output at a higher pressure than the pressure of the supply; and outlet means for exhausting said exhaust gases.
 4. Apparatus according to claim 3 wherein the propellant which drives said second turbine means is returned to the input to said second impeller means.
 5. Apparatus according to claim 3 further including at least a second catalyst means for receiving propellant from said output of said second impeller means and for decomposing propellant to exhaust gases, and at least a second outlet means for exhausting the exhaust gases from said second catalyst means.
 6. An ejector pumping system for pumping secondary fluid comprising: nozzle means so disposed and arranged with relation to the secondary fluid that discharge of primary fluid througH the nozzle means causes the pumping of secondary fluid; supply means for supplying propellant; impeller means having an input adapted to receive propellant from said supply means and having an output; catalyst means for receiving propellant from said output and for decomposing said propellant to form said primary fluid; turbine means adapted to be driven by primary fluid from said catalyst, said turbine means being adapted to drive said impeller means so that said impeller means pumps propellant to its output at a pressure higher than at its input; and outlet means for exhausting said primary fluid to said nozzle means.
 7. Apparatus according to claim 6 further including second impeller means having an input connected to said supply means and having an output connected to the input of said first-named impeller means, and second turbine means adapted to receive pressurized propellant from the output of said first-named impeller means to drive said second impeller means so that said second impeller means pumps propellant to its output at a higher pressure than the pressure of the supply.
 8. Apparatus according to claim 7 wherein the propellant which drives said second turbine means is returned to the input to said first-named impeller means.
 9. Apparatus according to claim 6 further including second catalyst means for receiving propellant from said output and for decomposing propellant to primary fluid, and second nozzle means for exhausting the primary fluid from said second catalyst means to pump said secondary fluid.
 10. Apparatus according to claim 5 wherein the propellant is a monopropellant. 